When conventional pressurized water reactors (PWR) are being shutdown, they are typically cooled by releasing steam from steam generators to decrease the operating temperature to about 250° F. Because further cool down using steam cooling becomes substantially ineffective around 250° F., continued cool down to a cold shutdown status (with operating temperatures less that 200° F.) is typically accomplished with an additional shutdown cooling system.
In conventional cooling systems a forced cooling system may be placed in service to lower the temperature of the primary coolant below 200° F. These shutdown cooling systems are typically dual purpose systems that require pumps to operate. The normal purpose of such systems is to transfer heat from the shutdown reactor to a water reservoir or heat sink via a heat exchanger. The alternate purpose of such systems is to inject large volumes of low pressure water following a reactor accident.
Because of the dual purpose of such cooling system, one of which is related to reactor safety, shutdown cooling systems typically require extensive maintenance and testing to ensure they are ready to perform their active safety function. In addition, the systems may be reliant on the continuous functioning of pumps, heat exchangers, piping, and one or more electrical sources to power the system, including redundancies.
Further, for other types of reactor modules that are designed to be moved during one or more operations, it may be necessary to first disconnect the pumps and/or electrical connections before moving the reactor module.
This application addresses these and other problems.